Work vehicles, such as tractors and other agricultural vehicles, include a hydraulic system configured to control the supply of hydraulic fluid to various on-board hydraulic components and/or various auxiliary hydraulic components, such as one or more hydraulic motors and/or cylinders included within an implement being towed by the vehicle. Conventional hydraulic systems utilize pressure-compensated flow control valve sections to modulate the flow of hydraulic fluid to the various auxiliary hydraulic components. In these conventional systems, a pump is configured to supply pressurized fluid to a flow control valve that regulates the flow of hydraulic fluid to a given hydraulic component. The load sensed at the flow control valve is then used to adjust the output pressure of the pump.
Such conventional hydraulic systems are capable of operating quite efficiently when supplying hydraulic fluid to auxiliary hydraulic components that do not require pressure control. However, when supplying hydraulic fluid to auxiliary hydraulic components that do require pressure control, conventional hydraulic systems have certain disadvantages. For example, many implements, such as planters and seeders, include a pressure regulating valve for adjusting the pressure of the hydraulic fluid supplied to the implement from the vehicle's hydraulic system to allow the implement to be operated in a constant down pressure mode. Such pressure control on the implement often results in the vehicle's hydraulic system not operating properly. Specifically, since the pump is operated based on the load sensed at the flow control valve, the vehicle's hydraulic system is unable to adapt to the downstream pressure control. This leads to the pump being operated at a significantly reduced efficiency and also leads to excessive heat generation. For example, since the flow control valve in a conventional hydraulic system is configured to provide a constant flow rate, the pump is often driven up to its maximum pressure output in an attempt to maintain such flow rate in instances when the auxiliary hydraulic component(s) requires a lesser flow rate due to the downstream pressure control.
Accordingly, an improved system for controlling the supply of hydraulic fluid to an implement of a work vehicle would be welcomed in the technology.